The present invention is directed to a spoolable coiled tubing mandrel that is positioned in a coiled tubing and is longitudinally flexible for spooling and gas lift valves that are wireline retrievable and longitudinally flexible and spoolable.
It is known, as disclosed in U.S. Pat. No, 5,170,815, to provide a longitudinally flexible and spoolable gas lift valve that is permanently mounted within the internal diameter of a coiled tubing. However, in order to repair or replace such valves, the coiled tubing string must be pulled in its entirety, and such permanently mounted valves prevent through tubing wireline work to be performed in the coiled tubing.
The present invention is directed to providing coiled tubing mandrels and gas lift valves that are not only longitudinally flexible for allowing their being spoolable on to the coiled tubing reel, but they have an external flush outside diameter of the same size as the coiled tubing, have an internal offset sidepocket which allows gas lift valves to be wireline inserted and retrieved from the mandrels, and the mandrels have a through bore for performing other wireline work without removing the gas lift valves. In addition, the gas lift valves may be of various types and are longitudinally flexible and spoolable and in one embodiment a gas lift valve is provided which may be opened, closed or provide any desired port size by control from the well surface.